single phase pad mounted transformer
GE Transformer’s single-phase pad-mounted transformers provide safe, tamper-proof, and weather-resistant underground power distribution. Featuring a dead-front design with side-by-side high and low-voltage compartments, they eliminate the need for expensive electrical vaults. Ideal for residential, commercial, and industrial applications, we deliver utility-grade reliability with an industry-leading 3 to 4 week lead time.
Exceeding North American Standards
Fully compliant with ANSI, IEEE, CSA, NEMA, and DOE 2016 efficiency standards. Every unit is strictly tested and holds UL/cUL and CSA certifications.
Key Technical Specifications:
- Capacity: 15 kVA to 250 kVA
- Primary Voltages: Up to 34.5 kV (BIL up to 150 kV); Radial or Loop Feed
- Secondary Voltages: 120/240 V, 240/480 V, 347/600 V, or custom
- Cooling (ONAN/KNAN): Premium Mineral Oil or eco-friendly FR3 fluid
- Enclosure: Carbon Steel or Stainless Steel; ANSI C57.12.28 compliant padlock
single phase pad mounted transformer
250 kva single phase pad mounted transformer
167 kva single phase pad mounted transformer
100 kva single phase pad mounted transformer
75 kva single phase pad mounted transformer
50 kva single phase pad mounted transformer
37.5 kva single phase pad mounted transformer
25 kva single phase pad mounted transformer
15 kva single phase pad mounted transformer
Standard & Optional Accessories
1. Fusing & Overvoltage Protection
Bayonet Expulsion Fuses in series with an isolation link.
Current-Limiting Fuses: Partial range ELSP current limiting fuses.
Surge Arresters: Under-oil distribution class surge arresters.
Secondary Protection: Low-voltage circuit breakers.
2. Switching & Tap Changing
Load-Break Switches: 2-position or 4-position (sectionalizing) switches, with provision for padlocking.
Tap Changers: Externally operable, no-load tap changers (e.g., 5-position).
Dual Voltage Switch: Externally operated switch for dual high-voltage ratings.
3. High & Low Voltage Bushings
HV Terminals: High-voltage bushing wells with load-break inserts and dust caps. Parking stand brackets included.
LV Terminals: Low-voltage bushings available in stud-type or customized spade-type configurations (4-hole, 6-hole, etc.).
4. Tank, Enclosure & Hardware
Tamper-Resistant Design: Flip-top hood (opens 180°) secured with a captive stainless steel pentahead door locking bolt.
Materials: Standard carbon-reinforced steel or highly corrosive-resistant 304/316L Stainless Steel tank and door.
Hardware: Recessed lifting provisions, foundation clamps, and laser-engraved stainless steel nameplates.
Coil Windings: High-efficiency Copper or Aluminum windings.
5. Gauges, Valves & Grounding
Gauges & Indicators: Liquid level sight gauge, dial-type temperature gauge, and pressure/vacuum gauge.
Valves: Automatic Pressure Relief Valve (PRV), drain & sampling valve with drip tray, and fill plug.
Grounding: Copper ground strap (X2 to ground), grounding spade terminals, and equipotential bonding device.
single phase pad mounted transformer Parameters
| Item | Single-Phase Pad-Mounted Transformer |
| Transformer Type | Loop feed & Radial feed |
| Capacity Range (kVA) | 10 kVA – 250 kVA |
| Primary Voltage (HV) | 34.5-19.92 / 13.8-7.957 / 13.2-7.62 / 12.47-7.2, 27.6/16, 14.4/7.2 kV or others |
| Secondary Voltage | 120/240 V, 240/480 V, 277 V, 347/600 V or others |
| Rated Frequency | 50 Hz / 60 Hz |
| Winding Material | Copper / Aluminum |
| Winding Connection / Vector Group | Subtractive Polarity (Single-Phase, 3-Wire) |
| Insulating Fluid | Mineral Oil / FR3 |
| Cooling Type | ONAN / KNAN |
| Tap Changer | ±2 x 2.5% Off-Circuit Tap Changer (OCTC) |
| Impedance | 2.0% – 4.0% (Or customized) |
| Average Winding Temp. Rise | 55°C (Based on 40°C Max Ambient) |
| Top-Oil Temp. Rise | 65°C (Based on 40°C Max Ambient) |
| Sound Level | ≤ 55 dB (measured at 1 meter) |
| Enclosure Material | Tamper-resistant steel tank (Optional: 304/316L Stainless Steel with C5-M grade anti-corrosion for coastal/marine environments) |
| Altitude | ≤1,000m or Customized |
| Ambient Temperature Range | -40°C to +50°C |
| Standards Compliance | ANSI C57.12.25, IEEE C57.12.25, IEC 60076 |
| Warranty | Typically one year, depending on the client’s specific needs |
| Delivery Time | Generally, it is 20-30 days. It is according to the quantity. |
| Min. order quantity | ≧ 1 set |
single phase pad mounted transformer Drawing
Factory Testing & Quality Control (FAT & QC)
100% Routine Testing Protocol
Our standard factory testing encompasses the following critical evaluations:
- Ratio & Polarity: Exact turns ratio verification across all tap connections and strict polarity confirmation.
- No-Load Losses & Excitation Current: Evaluated at 105% of the rated voltage and mathematically corrected to an 85°C reference temperature to accurately reflect field operating conditions.
- Load Losses & Impedance: Measured at the rated current on the specific high-voltage connection that yields the highest loss values, fully corrected to 85°C.
- Dielectric Withstand: Comprehensive insulation integrity verification through both applied voltage and induced voltage evaluations.
- Hermetic Seal Integrity: Rigorous pressure and leak detection testing is performed twice—first on the welded tank structures, and finally on the fully assembled unit (before PRD installation)—to guarantee absolutely zero insulating fluid leakage.
Type Tests & Special Evaluations (Upon Request)
For customized engineering projects or first-article utility approvals, we offer advanced design testing:
- Lightning Impulse Withstand Test (BIL verification).
- Temperature rise tests to validate thermal dissipation.
- Audible sound level testing (dB).
Flexible Factory Acceptance Testing (FAT)
We welcome complete transparency for major utility and EPC orders:
- In-Person FAT: Client engineers are invited to our facility to witness testing firsthand.
- Remote / Virtual FAT: High-definition live-streamed testing sessions with real-time data sharing.
- Third-Party Inspection: Seamless cooperation with global QA agencies like SGS, Intertek, or TUV.
Why Choose GE Transformer
Quality Control: Quality is a core value of GE Transformer. We conduct Factory Acceptance Testing (FAT), type testing, and third-party inspections to ensure superior quality. We strictly adhere to the ISO 9001 quality management system, committed to providing our customers with the highest quality products.
Professional Team: Our team comprises highly skilled professionals dedicated to responding quickly to customer needs. All GE Transformer team members receive systematic training and continuously improve their capabilities through rigorous quality standards and practices. Our commitment to customer service, product innovation, engineering excellence, and social and environmental responsibility makes us a trusted partner in the global power industry.
Certifications
- ISO9001：2015
- CE Certifications:
- UL Certifications:
- CSA Certification:
- CNAS Certification:
Competitive Market Pricing:Leveraging years of industry experience, GE Transformer integrates high-quality resources across R&D, production, procurement, transportation, and service, achieving effective cost control.
Fast Delivery: Strong production capacity, multiple freight partners, and a professional pre-sales and after-sales team, adhering to the “customer first” philosophy, provide customers with fast delivery and usage services.
FAQ
Q1: What is the practical difference in protection schemes between Radial Feed and Loop Feed configurations?
Radial feed units are typically equipped with a single set of high-voltage bushings for terminal end applications. Loop feed units feature a double set of high-voltage bushings (daisy-chain configuration) and are often paired with sectionalizing load-break switches and bayonet expulsion fuses to maintain grid reliability during isolated faults.
Q2: What type of insulating fluid is used in single-phase pad-mounted transformers?
Standard single-phase pad-mounted transformers utilize high-grade mineral oil, which provides excellent dielectric strength and thermal dissipation. However, for environmentally sensitive or high-fire-risk zones, GE Transformer offers advanced fluid options such as FR3 natural ester fluid. FR3 is fully biodegradable, non-toxic, and features a significantly higher fire point (360°C) compared to standard mineral oil (145°C). This makes it an ideal choice for enhancing project safety and extending the insulation lifespan under continuous load.
Q3: What anti-corrosion solutions do you provide for coastal or high-humidity environments?
For extreme marine or high-salinity environments, standard carbon steel is insufficient. We offer 304 or 316L stainless steel tanks and enclosures, combined with a rigorously applied C5-M grade anti-corrosion paint system. This ensures long-term operational integrity and drastically reduces maintenance costs in coastal areas.
Q4: How do you address insulation derating in high-altitude installations?
Standard units are designed for altitudes up to 1,000 meters (3,300 feet). For higher elevations where air density decreases, we engineer custom solutions with increased internal clearances, upgraded High Voltage BIL ratings, and specialized cooling designs to compensate for reduced dielectric strength and heat dissipation.
Q5: What custom engineering services do you provide for specific utility or EPC project requirements?
Our engineering team at GE Transformer works directly with your technical specifications to deliver highly tailored power solutions. Our customization capabilities include non-standard kVA ratings, specific impedance matching, tailored high-voltage tap configurations, and custom base dimensions designed to seamlessly fit existing concrete utility pads. We always provide comprehensive submittal drawings (Outline and Base Plans) for your engineering team’s approval prior to manufacturing.
Q6: What are the operational benefits of specifying a dead-front design with load-break inserts?
A: The dead-front configuration entirely encapsulates live high-voltage components. When paired with load-break bushing wells and inserts, it allows utility personnel to safely sectionalize cables and disconnect the transformer under load using standard hot-stick procedures. This maximizes operator safety and minimizes outage durations during grid maintenance.
Q7: How can these transformers be configured for specific environmental conditions?
Beyond standard kVA ratings, GE Transformer provides extensive customization to meet the exact technical demands of your deployment site. Buyers can select from a wide range of Optional Accessories, including pressure relief valves, load break switches, and specialized bayonet fusing. For coastal, marine, or heavy industrial environments, we offer advanced surface treatments such as ISO 12944 C5-M grade anti-corrosion coatings, ensuring long-term reliability and reducing maintenance costs in extreme conditions.
Q8: How does the externally operable dual high-voltage switch function in your units?
A: The optional dual-voltage switch allows utilities to seamlessly transition the transformer between two different primary voltage systems (e.g., upgrading a grid from 7.2 kV to 14.4 kV) without needing to replace the equipment. To ensure maximum safety and prevent arc flashing, this switch is strictly designed for de-energized operation only.